Attachment device for electrical equipment, such as an alternator/starter motor, in a clutch housing of an automobile

ABSTRACT

A device for attachment of electrical equipment, such as an alternator/starter motor, in the clutch housing of an automobile. The assembly includes a stator, a rotor, and a support hub of the rotor mounted on a bearing in an independent housing integral with the clutch housing.

[0001] The present invention concerns an attachment device forelectrical equipment, such as an alternator/starter motor, in the clutchhousing of an automobile.

[0002] Such devices are known according to which the electricalequipment is attached in the clutch housing situated between the gearboxand crankcase of the vehicle, the electrical equipment comprising afixed stator as integral part of the clutch housing and a rotor integralwith the engine crankshaft.

[0003] This known solution has the major shortcoming of requiring arelatively large air gap between the rotor and stator of about 0.8 mmbecause of the ovoid movements of the rotor in unison with thecrankshaft and problems of expansion of the clutch housing, made ofaluminum, during operation of the electrical equipment.

[0004] The invention proposes a device that permits a reduction in theair gap to a specified value and elimination of the problems ofexpansion of the clutch housing.

[0005] For this purpose, according to the invention, the attachmentdevice for electrical equipment, such as an alternator/starter motor, inthe clutch housing of an automobile and situated between the gearbox andcrankcase of the vehicle, the electrical equipment comprising a fixedstator relative to the clutch housing and a rotor that can be rotated bythe crankshaft of the engine, is characterized by the fact that theassembly comprising the stator, rotor and a support hub of the rotormounted on a bearing, such as a ball bearing, is housed in anindependent housing integral with the clutch housing and at a spacingtherefrom.

[0006] Preferably, the aforementioned assembly is pre-assembled in theindependent housing before attachment of this housing to the clutchhousing.

[0007] The bearing of the rotor support hub is mounted on a cylindricalcentral part of the independent housing coaxially surrounding theconnection shaft between the crankshaft and the input shaft of thegearbox.

[0008] The rotor support hub is connected by rotary coupling means to acover of the housing integral with the flywheel of the engine.

[0009] According to a first variant, the coupling means comprises acollar of elastomeric material, such as silicone, having on one sideaxially protruding and peripherally spaced hollow prismatic elementswith a rectangular base, which are mounted respectively in matchingcavities of the rotor support hub and a rigid metal collar having on oneside axially protruding and peripherally spaced prismatic elements withrectangular bases that are mounted respectively in the hollow prismaticelements of the elastomeric collar, the metal collar being integral onits side opposite the housing cover.

[0010] According to a second variant, the coupling means comprisesblocks of elastomeric material, such as silicone, respectively mountedin the circumferentially spaced matching cavities of the rotor supporthub, and cogs or pins integral on one side of the housing cover,parallel to the axis of rotation of the rotor and spacedcircumferentially, where said cogs or pins engage in holes made in theelastomer blocks.

[0011] Preferably, the independent housing comprises a lateral wallperpendicular to the crankshaft connected to the cylindrical centralpart by an oblique wall and a circular wall extending perpendicular tothe lateral wall so as to define the seat in which the aforementionedassembly is mounted by its introduction from the open side of thehousing opposite the lateral wall, the circular wall enclosing thestator of the electrical equipment on one part of it.

[0012] Advantageously, a circuit is provided to cool the electricalequipment.

[0013] Preferably, the cooling circuits consist of an annular bandcomprising a sealed annular chamber in which a cooling liquid cancirculate, such as a mixture of water and antifreeze, and this annularband is arranged on a circular external peripheral surface of thestator, is interposed between the circular wall of the housing and anannular attachment clamp of the stator in the housing, and is heldbetween these two parts by external connecting rods, one of the ends ofthe annular band being integral with one connecting rod and its othermobile end being connected to the connecting rod by a spring.

[0014] The annular band is attached to the independent housing by theexternal connecting rods parallel to the circular wall of the housing,anchored on one side to the housing and traversing on the other side anannular mounting clamp of the stator in the housing and being supportedclamped on the circular edge of the annular band opposite the circularedge of the circular wall of the housing.

[0015] The cooling circuit also comprises two external supply anddischarge tubes for cooling liquid in the annular chamber and areconnected in terms of fluid communication to the annular band.

[0016] The device also comprises a sleeve fixed in the cylindricalcentral part of the independent housing and permits guiding of adisengagement stop in translation.

[0017] According to one variant, the rotor support hub is made from asingle piece of aluminum. According to another variant, the rotorsupport hub comprises two flanges made of sheet metal attached to eachother by crimping.

[0018] The invention will be better understood and other purposes,characteristics, details and advantages thereof will be more readilyapparent in the following explanatory description with reference to theappended schematic drawings, given solely as examples and illustratingseveral variants of the invention, wherein:

[0019]FIG. 1 is a longitudinal section showing the attachment deviceaccording to the invention for electrical equipment in a clutch housingof an automobile;

[0020]FIG. 2 is a section similar to that of FIG. 1 showing only theclutch housing in which the partially depicted electrical equipment isattached;

[0021]FIG. 3 is a partial, enlarged cross section showing attachment ofthe housing of the electrical equipment to the clutch housing and themethod of sliding of the disengagement stop shown in its two engagementand disengagement positions;

[0022]FIG. 4 is an enlarged, exploded, perspective view of means thatpermit coupling of the rotor support hub of the electrical equipment tothe flywheel of the engine;

[0023]FIG. 5 is a view on a reduced scale along arrow V of FIG. 1 ofdifferent crankcases;

[0024]FIG. 6 is a partial cross-sectional view along line VI-VI of FIG.5;

[0025]FIG. 7 is a partial cross-sectional view along line VII-VII ofFIG. 5;

[0026]FIG. 8 is a partial cross-sectional view along line VIII-VIII ofFIG. 5;

[0027]FIG. 9 is an external, enlarged, perspective view of part of theelectrical equipment and its housing with a cooling circuit for thisequipment;

[0028]FIG. 10 is a front view of an annular band intended to define acooling chamber of the cooling circuit;

[0029]FIG. 11 is a front view of a variant of the rotor support hub ofthe electrical equipment;

[0030]FIG. 12 is a cross-sectional view along line XII-XII of FIG. 11;

[0031]FIG. 13 is a cross-sectional view along line XIII-XIII of FIG. 11,and

[0032]FIG. 14 is a cross-sectional view similar to that of FIG. 1showing another variant of the attachment device of the invention.

[0033] FIGS. 1 to 10 show the first variant of the attachment device forelectrical equipment 1, such as a alternator/starter motor, in a clutchhousing 2 attached between the gearbox 3 and crankcase 4 of anautomobile.

[0034] An electrical apparatus simultaneously forming a generator andvehicle starter, known per se, is described, for example, inInternational Patent Application WO 99/22955.

[0035] Thus, the alternator/starter motor 1, which is schematicallyshown in the figures, essentially comprises an annular stator 5 fixedrelative to the clutch housing 2 and an annular rotor 6 housed in thisfixed stator 5 and defining an air gap relative to it.

[0036] The rotor 6 is rotated by the crankshaft 7 of the internalcombustion engine, as will be seen later.

[0037] The different components situated in the gearbox 3 are alreadyknown per se and do not require description, except for the fact thatreference numeral 8 denotes the differential of the vehicle housed in ahousing 9 and that the wheel axle is denoted by reference numeral 10.

[0038] As shown, rotor 6 is mounted integral on a support hub 11, itselfmounted to rotate on a bearing 12, such as a ball bearing.

[0039] Rotor 6 is held axially on hub 11 on one side by a shoulder 13 ofhub 11 and on the other side by an annular collar 14, visible in FIG. 3.

[0040] According to the invention, the assembly consisting of stator 5,rotor 6, hub 11, and bearing 12 is mounted in independent housing 15attached by part of it to the clutch housing 2 by attachment screws V,as clearly follows from FIG. 3, so that the housing 15 is mounted in theclutch housing 2 and spaced therefrom, without being in contact with it,except for the attachment sites via screws V of the housing part 15 toclutch housing 2.

[0041] Housing 15 comprises a tubular central part 16 that coaxiallysurrounds a connection part 17 of crankshaft 7 to the input shaft 18 ofthe gearbox 3. Bearing 12 is mounted on the tubular central part and isheld axially on it by a stop shoulder 16 a situated on one end of part16 and a circlip 19 in the vicinity of its end, as will be seen later.Hub 11 is also held axially on bearing 12, on the one hand, by a circlip20 mounted in an internal groove of the hub and, on the other hand, by ashoulder 21 of hub 11 supported on bearing 12.

[0042] Housing 15 also comprises a lateral wall 22 that extendsperpendicular to the axes of crankshaft 7 and is connected to thecentral tubular part 16 via an oblique wall 23. Housing 15 comprises acircular part 24 that extends the upper part of the lateral wall 15,extending perpendicular to it and enclosing stator 5 on its externalcircular peripheral surface. FIGS. 1 and 2 show that the wall 24 onlycovers part of the periphery of stator 5 in the axial direction.

[0043] It is apparent from the description above that the assemblyconsisting of stator 5, rotor 6, hub 11 and bearing 12 is pre-assembledin the plant in the housing 15 by introducing it from the open sideopposite wall 22 and attached in it, whereupon housing 15 is fastened tothe clutch housing by attachment screws V.

[0044] With this arrangement, a strictly constant air gap of 0.5 mm isobtained, which permits excellent performance of the electricalequipment.

[0045] The support hub 11 of rotor 6 is connected by coupling devices toa housing cover 25, which rotates in unison with flywheel 26 of theengine via rivets R, the flywheel being entrained by the crankshaft 7.These connection devices, as better follows from FIG. 4, include acollar 27 made of elastomeric material, such as silicone, having on oneside a certain number of hollow prismatic elements with axiallyprotruding rectangular bases 28 that are circumferentially spaced atequal intervals and are attached in cavities of corresponding shape 29circumferentially formed at equal intervals in hub 11.

[0046] The connection means also includes a rigid metal collar 30comprising, on one side, prismatic elements with axially protrudingrectangular bases 31 that are spaced circumferentially at equalintervals and are fastened respectively in the hollow elements 28 of theelastomer collar 27 on the other side. The metal collar 30 is attachedon its side opposite the protruding elements 31 to the housing cover 25by means of rivets that pass through holes 32 of the collar 30 formed inthe connection parts between the protruding elements 31.

[0047] Thus, the form of the rigid collar 30 matches the elastomercollar 27, and the two collars are assembled in hub 11 so as to form arelatively compact assembly. The protruding elements 28 of the elastomercollar 27 are active elements in the two directions of rotation of therotating electrical equipment and have sufficient dimensions to transmitthe necessary torque.

[0048]FIG. 3 more clearly shows that a sleeve 33 is attached in thecentral part 16 of housing 15 and serves as means of translatory guidingwithin it of the disengagement stop 34, which is shown in thedisengagement position in the upper part of FIG. 3, whereas it occupiesthe engagement position in the lower part of FIG. 3. The disengagementstop 34, as is known per se, is moved by a control bracket 35 mounted torotate on clutch housing 2 by a pivot pin 36 so as to controltranslatory movement of the disengagement stop 34, which acts on its endopposite bracket 35 on a clutch diaphragm DE, which itself acts on theclutch plates PE. The circlip 19 for axial holding of bearing 12 ismounted in a radially external groove of bracket 33.

[0049] Bracket 33, which permits guiding of disengagement stop 34 fromthe outside, has the advantage relative to the conventional knownsolutions of not causing troublesome vibrations. According to the knownsolutions, the disengagement stop is guided on a tube, i.e., it slideson this tube; to adapt this solution to the invention would result inincreased length of the guide tube and, as a result, the generation ofvibration.

[0050]FIGS. 2 and 9 also show that the stator 5 is held in position inhousing 15 by connecting rods T situated on the outside of the circularwall 24 of housing 15 and extending parallel thereto, anchored on oneside to housing 15 and traversing on the opposite side an annular clampB so that by tightening the nuts of connecting rods T, the annular clampB axially forces stator 5 against the internal face of lateral wall 22.

[0051] As follows in particular from FIG. 4, the support hub 11 of rotor6 is made from a single piece of aluminum. According to the variantdepicted in FIGS. 10 to 12, hub 11 is made from two flanges of sheetmetal, 11 a, 11 b, fastened to each other by crimping at the level ofholes 11 c formed in the two flanges. More precisely, the circular edgeof each hole of one of the flanges, for example, flange 11 b, is curvedby deformation to clamp the circular edge of the hole corresponding tothe other flange. Of course, the external periphery of the two flanges 1a, 1 lb forming the hub has a geometric configuration similar to that ofthe periphery of hub 11, which is the object of the variant justdescribed with reference to FIG. 1, for holding rotor 6 thereon.

[0052] FIGS. 1 to 10 also show the presence of a cooling circuit for theelectrical equipment 1.

[0053] This cooling circuit consists of an annular band 39 containing asealed annular chamber 37 in which a cooling liquid circulates. Thisannular band is arranged on the external circular peripheral surface ofstator 5.

[0054]FIG. 9 in connection with FIG. 2 shows that the annular band 39 isinterposed between the circular wall 24 of housing 15 and the clamp Band is held with axial play between these two parts by connecting rodsT. FIG. 10 shows attachment of the ends of the annular band 39 in whichone of the ends 39 a of the band is integral with the connecting rod T,whereas its other mobile end 39 b is connected to connecting rod T by aspring R, thus permitting compensation for expansion of the electricmachine.

[0055] Supply of cooling liquid, such as water, into the cooling chamber37 occurs through a tube 40 connected to annular band 39 and dischargingthrough it to be in fluid communication with chamber 37. The output ofcooling liquid occurs through a tube 41 also in fluid communication withthe cooling chamber 37 through annular band 39.

[0056]FIG. 14 shows a variant of the means of connection of the supporthub 11 of rotor 6 to the clutch housing 25.

[0057] These means of connection include a certain number of blocks 42made of elastomer material, such as silicone, which are fastenedrespectively in matching cavities 43 made circumferentially at equalintervals in support hub 11.

[0058] The housing cover 25 rotates in unison with the elastomer block42 by means of cogs or pins 44 integral with the housing cover 25 andextending on one side of it, being spaced circumferentially at equalintervals. The cogs 44 are engaged in the holes of the elastomer blocks42 and attached therein, extending parallel to the crankshaft 7 by meansof metal sleeves 45 attached in the elastomer blocks, which exert radialforces on sleeves 45 directly toward cogs 44 to block them in sleeves45. The latter are well fixed in their corresponding cavities 43 bybeing force-fit.

[0059]FIG. 14 also shows that the independent housing 15 is attached tothe clutch housing 2 by a certain number of pins 46, only one of whichis shown, traversing the lateral wall 22 of housing 15 and force-fit inthe corresponding blind holes of clutch housing 2.

[0060] The device of the invention described in the first and secondvariants permits attachment of electrical equipment 1 in the clutchhousing 2, eliminating problems of positioning of the air gap of theequipment and problems of expansion of the aluminum clutch housingduring operation of the electrical equipment. Moreover, factorypre-assembly of the different components of the electrical equipment inthe independent housing 15 permits an appreciable saving of assemblytime and, as a result, a reduction in cost. Moreover, this also has theadvantage of permitting verification of operation of the electricalmachine and its performance.

1. Attachment device for electrical equipment, such as analternator/starter motor, in a clutch housing (2) of an automobile,situated between the gearbox (3) and the crankcase (4) of the vehicle,the electrical equipment (11) comprising a stator (5) fixed relative tothe clutch housing (2) and a rotor (6) that can be rotated by thecrankshaft (7) of the engine, characterized by the fact that theassembly comprising the stator (5), rotor (6) and support hub (11) ofrotor (6), mounted on a bearing (12), such as a ball bearing, is mountedin an independent housing (15) integral with clutch housing (2) andspaced therefrom.
 2. Device according to claim 1 , characterized by thefact that the aforementioned assembly is pre-assembled in theindependent housing (15) before attachment of the latter to the clutchhousing (2).
 3. Device according to claim 1 or 2 , characterized by thefact that the bearing (12) of the support hub (11) of rotor (6) ismounted on a cylindrical central part (16) of the independent housing(15), coaxially surrounding the connection shaft (17) between crankshaft(7) and input shaft (18) of the gearbox.
 4. Device according to one ofthe preceding claims, characterized by the fact that the support hub(11) of rotor (6) is connected by rotary coupling means (27, 30) to anintegral housing cover (25) of the flywheel (26) of the engine. 5.Device according to claim 4 , characterized by the fact that theaforementioned coupling means comprises a collar (27) made of anelastomeric material, such as silicone, having on one side hollowprismatic elements with axially protruding rectangular bases (28) thatare circumferentially spaced and attached in corresponding cavities (29)of the support hub (11) of rotor (6), and a rigid metal collar (30),which has on one side prismatic elements with axially protrudingrectangular base[s] (31) that are circumferentially spaced and areattached in the hollow prismatic elements (28) of the elastomeric collar(27), the metal collar (30) being integral on its side opposite thehousing cover (25).
 6. Device according to claim 4 , characterized bythe fact that the aforementioned coupling means comprises blocks (42) ofelastomeric material, such as silicone, attached in circumferentiallyspaced corresponding cavities of the support hub (11) of rotor (6) andcogs or pins (44) on one side of the housing cover (25) parallel to theaxis of rotation of rotor (6) and circumferentially spaced, the cogs orpins (44) engaging respectively in the holes made in the elastomerblocks (42).
 7. Device according to one of the claims 3 to 6 ,characterized by the fact that the independent housing (15) contains alateral wall (22) perpendicular to crankshaft (7), connected to thecylindrical central part (16) by an oblique wall (23) and a circularwall (24) extending perpendicular to lateral wall (22) so as to definethe housing in which the aforementioned assembly is mounted byintroduction of it from the open side opposite the lateral wall (22). 8.Device according to one of the preceding claims, characterized by thefact that it includes a cooling circuit for the electrical equipment(1).
 9. Device according to claim 8 , when considered in combinationwith claim 7 , characterized by the fact that the cooling circuitconsists of an annular band (39) containing a sealed annular chamber(37) in which a cooling liquid circulates, the annular metal band (39)being arranged on the peripheral surface of stator (5).
 10. Deviceaccording to claim 9 , characterized by the fact that the annular band(39) is interposed between the circular wall (24) of housing (15) and anannular bracket (B) for attachment of stator (5) in housing (15) and isheld between these two parts by external connecting rods (T), and by thefact that one of the ends (39 a) of annular band (39) is integral withthe connecting rod (T) and its other mobile end (39 b ) is connected tothe connecting rod (T) via a spring (R).
 11. Device according to claim 9or 10 , characterized by the fact that the cooling circuit contains twotubes (40, 41) respectively for supply and discharge of cooling liquidin the annular chamber (37) and connected in fluid communication toannular band (39).
 12. Device according to one of the preceding claims,characterized by the fact that it comprises a sleeve (33) fixed in thecylindrical central part (16) of independent housing (15) and permittingtranslatory guiding of a disengagement stop (34).
 13. Device accordingto one of the preceding claims, characterized by the fact that thesupport hub (11) of rotor (6) is made from a single piece of aluminum.14. Device according to one of the claims 1 to 12 , characterized by thefact that the support hub (11) of rotor (6) contains two sheet metalflanges (1 la, 1 lb) attached one to the other by crimping.